   "Asynchronously point a session to a url. Destroy the session if the
   webdriver is dead. Return true if everything seems okay."
   (let [okay (not (session-go-to-url session-id current-url))]
-    (when (not okay) (destroy-session session-id))
+    (if-not okay (destroy-session session-id))
     okay))
 
 (def ModifyArg

      (session-key session-id)
      (select-keys session
        [:reserved :current-url :browser-name :node]))
    (when (contains? session :tags)
      (save-session-tags-to-redis session-id (session :tags)))))

(defn modify-session

               :as modifications}]
  (info (format "Modifing session %s, %s" session-id (str modifications)))
  (when (some #{session-id} (session-ids))
    (if (or (not current-url)
            (session-go-to-url-or-destroy-session session-id current-url))
      (save-session-diff-to-redis
        session-id
